1. Field of the Invention
The present invention pertains to disease-specific markers for cancer and hyperplasia of the human prostate. Specifically, the present invention pertains to disease-specific markers suitable for diagnosing and monitoring the treatment of cancer and hyperplasia of the human prostate.
2. Brief Description of the Prior Art
The two major diseases of the human prostate are cancer and hyperplasia. While some investigators theorize that hyperplasia is an early state of cancer activity, others feel that it is a totally unrelated disease. The incidence of both cancer and hyperplasia of the prostate accelerate after the age of fifty. In the United States, in men past the age of fifty, the age gradient for cancer of the prostate is steeper than that of any other cancer site, and prostate cancer is the foremost killer of men seventy years of age and older. While seemingly related to aging the actual molecular mechanisms of the cause and devastating growth of cancer are not yet understood.
Computed tomography scanning, ultrasound, aspiration techniques and definitive pelvic lymph node disections have contributed toward assessment of the extent of prostate cancer. However, the use of these methods in diagnosing, treating and understanding prostatic cancer are dubious.
In the past two decades, isolation and measurement of prostatic specific acid phosphatase has been proposed as a means for diagnosing and monitoring the treatment of prostatic cancer. Several tests utilizing radioimmunoassay, counterimmune electrophoresis, etc., have been utilized to detect circulating acid phosphatase of prostatic origin. While initially accepted with great enthusiasm, it has become apparent that wide variations of results exist with these methods. Consensus is emerging that use of such methods for detection of unsuspected cancer of the prostate in the general population would not be feasible due to the large number of falsely positive results.
Changes in normal serum glycoprotein levels have long been associated with malignancy. Recent investigations have confirmed that changes in specific glycoprotein do indicate cancer activity. See "Preparation and Properties of Glycoprotein Associated with Malignancy", Bolmer, Sally Delong, and Davidson, Eugene A., (1981), Biochemistry 20: 1047. However, changes in glycoprotein levels are not specific to prostate cancer.
Very recent investigation of serum prostate-specific antigen (PA) and prostatic acid phosphatase (PAP) indicate that a multiple marker test of tissue specific antigens may be of additive value in the immunodiagnosis of cancer. See "Multiple Marker Evaluation in Human Prostate Cancer with the Use of Tissue Specific Antigens", Kuriyama, M.; Wang, M. C.; Lee, C. L.; Killian, C. S.,; Papsidero, L. D.; Inaji, H.; Loor, R. M.; Lin, M. F.; Nishiura, T.; Slack, N. H.; Murphy, G. P. and Chu, T. M., JNCI 1982; 68:99. The same investigation refers to the present unavailability of human tumor-specific markers for prostate cancer.
A marker-molecule that is specific for cancer could offer impetus toward the understanding of the biochemical process involved in cancer. A good marker-molecule would identify the disease and would act as a guide for the various stages of cancer. It would be good for diagnostic, prognostic, and treatment purposes. Unfortunately, as already pointed out, cancer specific marker molecules of the prostate have been elusive and difficult to discover.